A freestanding polypyrrole hybrid electrode supported by conducting silk fabric coated with PEDOT:PSS and MWCNTs for high-performance supercapacitor

In this paper, a hierarchical hybrid silk fabric-based (SF) electrode is fabricated via a simple two-step process, including Poly (3,4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT:PSS) and multi-walled carbon nanotube (MWCNT) drop-coating and polypyrrole (PPy) in-suit electrodeposition for symmetric supercapacitors, which shows a low sheet resistance (1.57 ± 0.11 Ω sq⁻¹), outstanding capacitance of 5296 mF cm⁻² at 2 mA cm⁻² and excellen cycling performance. The splendid electrochemical performance can be attributed to the combination of the assorted composites, PEDOT:PSS and PPy provide superior conductivity and large faradaic pseudocapacitance, the doping of MWCNT significantly improves the cycling performance of the composite electrodes, and the unique hierarchical structures of SF provide a large accessible area for the active composites loading. Moreover, the symmetric supercapacitor shows a highly capacitance of 1088.6 mF cm⁻² (13.44 F cm⁻³) at 2 mA cm⁻², and energy density of 1.87 mWh cm⁻³ at a power density of 12 mW cm⁻³ with good cycling stability. In addition, the device features easy fabrication, low-cost and long-term cycling life, which indicates it can be a promising energy storage device in the future.